New insights from non‐invasive imaging: from prospection of skin photodamages to training with mobile application

Abstract

The incidence of non‐melanoma skin cancer is on the rise and melanoma is among the most common cancers in the United States. Establishing an early diagnosis is essential for improving the prognosis of patients with skin cancer. High‐resolution non‐invasive imaging techniques may represent key tools for helping to identify and monitor early signs of skin cancer in seemingly healthy skin. Cumulative lifetime sun exposure leads to photoaging and photocarcinogenenis and the reaction of the skin to this solar‐induced damage is balanced between the DNA repair and photoprotection defence mechanisms of melanocytes and keratinocytes. In the first part of this article we provide an overview of these defence mechanisms and of the photoaging process, and discuss how non‐invasive imaging can be used to evaluate these changes. We then propose a model in which skin aging manifestations can be classified according to subject‐specific sun‐damage reaction profiles observed by reflectance confocal microscopy (RCM) and optical coherence tomography (OCT). These photoaging profiles include an atrophic phenotype characterized by actinic keratosis, and a hypertrophic phenotype characterized by hyperplastic pigmented skin. According to our model, these phenotypes may be predictive of predispositions to different types of skin cancer: squamous cell carcinoma for the atrophic phenotype and lentigo maligna and freckles for the hypertrophic phenotype. In addition to RCM and OCT, dermoscopy is another non‐invasive technique that has improved the diagnosis of skin cancer. In the second part of this article, we describe how the YouDermoscopy™ application can improve skills and thus enhance the dermoscopic recognition of sun‐induced skin tumours, and then show how this training tool enables its users to collaborate with dermatologists worldwide to obtain second opinions for the diagnosis of ambiguous lesions. Altogether, RCM, OCT and dermoscopy are valuable tools that can contribute significantly to improving the early diagnosis of precancerous and cancerous lesions.

Photoprotection: Current developments and controversies

“…5 Patients with features of both phenotypes (mixed) have also been observed in clinical practice. 2 A study of facial photoageing using skin biopsies from 20 AP and 20 HP individuals assessed histologically and by immunohistochemistry confirmed that the two clinical phenotypes have distinct histological characteristics. 6 HP facial skin exhibits severe solar elastosis, whereas in AP facial skin, solar elastosis is more marked in males.…”

“…1 The photodamage caused by photoageing is superimposed on the changes caused by chronologic ageing (intrinsic ageing) and comprises the age-associated features of skin appearance such as fine and coarse wrinkles and uneven skin colour (erythaema, telangiectasia, dyspigmentation, and sallowness). 2 In general, lighter skin (lower Fitzpatrick phototype) is more susceptible to photoageing and photocarcinogenesis than darker skin (higher Fitzpatrick phototype). 3,4 Different photoageing pathways lead to different ageing phenotypes, different skin cancer risks and different targets for anti-ageing approaches.…”

“…Non-invasive imaging such as reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) has allowed the two photoageing phenotypes to be described more thoroughly. 2 The AP phenotype has been shown by RCM to be characterized by dyskeratosis and with OCT by a thin epidermis revealing epidermal atrophy. Actinic keratosis (AK) may be present with more marked dyskeratosis and epidermal profile alterations, with a heterogeneous thickness.…”

Age-Related Dysfunction in Balance: A Comprehensive Review of Causes, Consequences, and Interventions

“…6) Mobile application [162]: There are various mobile applications (Apps) designed for balance assessment and training. These apps typically use built-in sensors in a smartphone or tablet to measure postural sway and provide interactive exercises to improve balance.…”

Line‐field confocal optical coherence tomography in dermato‐oncology: A literature review towards harmonized histopathology‐integrated terminology

“…First published in 2018 and approved as a medical device in Europe in 2020, line‐field confocal optical coherence tomography (LC‐OCT) is a real‐time, non‐invasive imaging technology that offers an optical resolution of ~1 μm, with details of cellular and structural skin components comparable to histopathology. Unlike other established techniques such as reflectance confocal microscopy 16 (RCM) and optical coherence tomography (OCT), 17–20 the skin surface and underlying tissue morphology can be viewed simultaneously at high magnification with combined video‐dermoscopy and en‐face and cross‐sectional images 21 . Videos can be recorded and three‐dimensional volumes can be obtained from stacking en‐face or cross‐sectional images, which can be coupled with quantitative analysis integrated in the user type of scan 22,23 .…”